Digital control of the sound effects of a musical instrument

ABSTRACT

The object of the present invention concerns a control device ( 100 ) for a generation module (GM) of sound effects (EF A , EF B ) of a musical instrument (MI), such device comprising computer software configured for: —the capture, using a digital camera ( 10 ), of at least one digital image (I) comprising at least one portion of the user&#39;s (U) face; —processing of such at least one image (I) to define expression data (D_EX i , i being a positive integer) containing information relating to facial expressions (EX a , EX b ) of the user (U); —an analysis of such expression data (D_EX i ) using a predefined first database (DB 1 ) to determine a sound effect data (D_EF j , j being a positive integer) containing information relating to at least one sound effect (EF A , EF B ) corresponding to the facial expression (EX a , EX b ) of the user (U).

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromprior French Patent Application No. 13 53624 filed on Apr. 19, 2013 inFrance, the entire contents of which are incorporated herein forreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of sound effect control formusical instruments.

More specifically, the present invention aims to facilitate digitalcontrol of sound effects of a musical instrument for musicians.

The present invention therefore has several useful applications in thefield of music, particularly for controlling the sound effects of amusical instrument such as a guitar. Evidently, other usefulapplications may also be conceived by using the digital control proposedherein according to the present invention.

2. Description of the Related Art

Electronics and computer software now hold a central place in the fieldof music production: indeed, electronics and computer software enablethe transformation and/or synthesis of new sounds to enrich musicalcompositions. The present description entirely focuses on sound effects.Purely illustrative and non-restrictive examples include effects such as“fading”, audio filtering, echo, or the creation of asynthetic/electronic sound or reading a sound from a predetermined soundbank, etc.

However, the possibilities for a musician to physical interact withelectronic and computer software interfaces to control these soundeffects often remain incompatible with those offered by physical musicalinstruments. As such, using such interfaces can often actuallycompromise the musical performance itself.

These control interfaces generally comprise a mouse, a keyboard and ascreen (sometimes tactile) one or several potentiometers, or one orseveral pedals, etc.

The Applicant observes that such interfaces are difficult for a musicianusing their hands and/or feet to play their instrument to manipulate: aguitarist has one hand on the neck of their guitar and their other handoccupied strumming the strings; a pianist generally has both hands onthe piano keys and their feet engaged in operating the pedals; a DiscJockey has one hand on the vinyl disc and the other on the crossfader oftheir mixing table.

Studying these interfaces more closely, we can currently distinguishseveral techniques which enable musicians to control sound effects: useof manual controls, foot controls, mouth controls or the use ofvocoders.

Manual control interfaces are one of the most common solutions forcontrolling sound effects: yet these interfaces usually enable the userto independently control only one parameter at a time; these manuallyactivated interfaces are moreover not particularly accessible tomusicians such as guitarists, whose hands are occupied playing theirinstrument. As such, these interfaces are generally only used to modifysound loops which have already been recorded and/or to set the soundbefore playing.

Use of foot-controlled interfaces (or a pedal) is another classic way tocontrol sound effects. However, when using a pedal, as when using amanual controller, it is only possible to control one parameter at atime. Moreover, when using a pedal, the musician cannot move around onstage as they would like to. Furthermore, using a pedal is difficult forboth spatial and temporal precision: it requires both dexterity and alot of practice.

Alternatively, there are certain interfaces which enable sound effectcontrol using the mouth: this is known as the “talk box”. Morespecifically, the talk box is a device which enables amplified sounds tobe modified using the mouth.

This device is in the form of a tube which the musician places in theirmouth. This tube consists of a pipe in which the sound produced by aguitar, for example, is disseminated. The tube is thus connected to afunnel located opposite the loudspeaker of the guitar. As such, when themusician plays, the sound travels up the tube to their mouth, where itis then adjusted by the variable openings of the mouth; the form of themouth cavity, and the position of the mouth and/or lips of the musician.The guitar therefore “speaks” according to the musician's mouth cavity.The microphone then captures the sound.

The disadvantages of such controller are numerous: beyond theunaesthetic appearance of this device, which requires keeping a tube inthe mouth, such device only enables the control of one type of effect:acoustic filtering using the mouth.

The Applicant moreover argues that such device is not popular among manymusicians.

Among existing sound effect controllers, there is the vocoder. Thevocoder is an electronic sound signal processing device which analysesthe main spectral components of a voice or another sound, and whichmakes a synthetic sound from such analysis.

The disadvantages of the vocoder are numerous: such a system onlyenables the control of one type of effect, filtering via spectralenvelopment of the sound emitted by the mouth. Moreover, where thebackground acoustic sound is used, such system is sensitive tobackground noise.

As such, the Applicant argues that the prior art identified hereabovedoes not provide satisfactory solutions to enable musicians to easilyand effectively control the sound effects of a musical instrument.Indeed, none of the approaches proposed in the prior art enables preciseand easy control of several sound effects simultaneously while enablingthe musician to move around freely (on stage, for example).

SUMMARY OF THE INVENTION

The present invention aims to improve the situation described hereabove.

As such, the present invention provides a simple and clever solution forcontrolling the sound effects of a musical instrument.

The present invention therefore regards a control process for ageneration module of sound effects to control the sound effects of amusical instrument.

The process according to the present invention is implemented using acomputer software and comprises an acquisition stage which consists ofcapturing, using a digital camera, at least one digital image comprisingat least a portion of the user's face (here, a musician, for example).

The concept underpinning the present invention is to exploit currentimage processing techniques to recognize, within the captured image, atleast one expression within at least a portion of the user's face and tocontrol, according to each expression, one or several sound effects of amusical instrument.

As such, the process according to the present invention comprises aprocessing stage which consists of processing such at least one image,captured during the capture stage, to determine one or severalexpression data containing information relating to at least one of theuser's facial expressions (for example, the degree of vertical openingof the mouth, the degree of frowning eyebrows, a wink, or similaritywith a general facial expression: “sad”, “happy”, “surprised”, “scared”,weighting between several per-recorded general facial expressions,etc.).

By ‘facial expression’ in the sense of the present invention, andthroughout the present description which follows, a facial expressionmay be:

-   -   either general: concerning a general facial expression, for        example, when the user manifests a “sad”, “happy” or “surprised”        expression,    -   or localized: for example, when the user makes a movement        (expression) with a portion of their face (wink, opening the        mouth, frowning eyebrows, etc.).

By expression recognition, in the sense of the present invention, andthroughout the present description which follows, is meant a continualrecognition of expressions.

In other words, the recognition of facial expressions during theprocessing stage is not binary, it rather enables the recognition ofintermediary expressions between pre-established expressions, byproviding expression data relating, for example, with expressionpercentages (in comparison to a neutral expression), or with weightingbetween several expressions, or similarity values relating to differentexpressions.

According to the present invention, a predefined first databasecomprises a multitude of expression data, each of which is associatedwith one or several sound effect data.

As such, in this database, there is a pre-established relationship,which may be configured by the user before use, between one or severalfacial expressions (for example, opening of the mouth measuring aspecific diameter) and one or several sound effects (for example, asound effect such as “fading” and/or echo). It is therefore possible toenvisage that a facial expression could be associated with several soundeffects. The present invention therefore makes it possible to controlseveral sound effects simultaneously, with no restriction on the numberof sound effects.

By enabling an association between an expression and one or severalsound effects, the database enables the user to define the desired soundresult for a certain number of expressions.

Furthermore the database allows the user to configure the behavior ofthe sound effects to the intermediate expressions (for example, a “soundmorphing” between the effects associated with the various expressions).

The behavior of the sound effects between or around the expressionsrecorded in this database may be of a different kind. For example andnon-restrictively: a progressive sound morphing as an expression isprogressively formed according to a curve, or the trigger of the soundeffect associated with an expression, above a threshold of similaritybetween the user's actual expression and such expression, etc. . . . .

The process according to the present invention exploits thisrelationship between sound effect data and expression data.

For this, the process according to the present invention comprises ananalysis stage during which the expression data, which were definedduring the processing stage, are compared with this first database todetermine one or several new sound effect data, each of which containinformation relating to the sound effect(s) corresponding to the user'sfacial expression(s).

This analysis therefore uses a correspondence map between the soundeffect data and the expression data, which is recorded in the database.

As such, when the user changes from one expression to another, theanalysis can, for example, determine new sound effect data which passescontinuously from the first sound effect data associated with the firstexpression, to the second sound effect data associated with the secondexpression, from the expression data (containing the weighting of thetwo expressions) and the correspondence map. This is called “soundmorphing”.

As such, this succession of technical stages, characteristic of thepresent invention, enables digital control of the sound effects of amusical instrument via one or several of the musician's facialexpressions.

The present invention therefore enables a musician to (simultaneously)control the desired sound effects while his hands and feet remain freeto play his instrument. The musician can also, using the presentinvention, move around freely on stage.

Using the present invention, the musician can, according to theirpresettings, control and produce a very large range of sound effects.

The capture stage uses a camera which is sensitive to near-infraredwavelengths.

The capture stage also comprises the emission of a source of light,preferably of infrared wavelength ranging between approximately 700 to3000 nanometers, and preferably uniformly, in the direction of theportion of the user's face.

The capture stage also comprises the use of an optical filter whichpreferably only allows the passage of a frequency band set around to thefrequency of the emitted light, before the capture of each image. Thisremoves all other frequencies corresponding to other light sources whichcould potentially perturb the recognition of expressions.

As such, the musician can control the sound effects of their musicalinstrument in a concert environment, for example, an environment withlow or changing lighting (for example, light sets with spotlights).

According to one variation, the capture stage consists of capturing atleast two digital images. In this variation, the process usefullycomprises a temporal interpolation stage during which expression data orsound effect data which are determined after the analysis stage, areinterpolated to obtain a multitude of intermediary sound effect databetween two successive digital images.

This ensures the quality of the sound effects. Indeed, a conventionaldigital camera captures images generally at a frequency that is betweenabout 25 and 200 images per second.

The time interval between two successive images therefore ranges between5 and 40 milliseconds.

As such, an expression data, and thus a sound data, is sent every 5 to40 milliseconds to the generation module of sound effects. However, thehuman ear is sensitive to shorter time intervals. As such, without thisinterpolation stage, the perceived sound could present a “stairwayeffect”. To resolve this problem, the present invention incorporates theinterpolation of values of expression data or sound effect data betweentwo images, and sending intermediary values between these to produce a“smooth” sound.

The present invention therefore envisages the application of a temporalinterpolation algorithm which sends intermediary values.

This interpolation stage can also interpolate expression data.

The processing stage comprises the application of an image processingalgorithm for each digital image captured to recognize the user's facialexpression(s). For example, computer image processing algorithmsenabling the automatic recognition of a shape or movement in an image orsuccession of images.

Recognition of the user's facial expression(s) may also be implementedvia recognition of facial descriptors (for example, the parameters of a3D model of a face recognized in the image, or distinctive pointcoordinates in the image), and analyzing such information by comparingit to a second database comprising a predefined bank of expressions(predetermined or recorded by the user).

In other words, the processing stage comprises a comparison betweenfacial descriptors (here, for example, the parameters of a 3D model of aface recognized in the image, or distinctive point coordinates in theimage, etc) and a second database comprising a mapping between facialdescriptors and one or several facial expressions predefined or recordedby the user.

This second database enables the user to record their own expressionsand thus obtain customized recognition of personal expressions.

Expressions in this database can be learned from facial images capturedby the camera. It also enables the user to record new expressions from“photographs” or video capture.

As such, the user can easily record the expressions which certain soundresults (i.e. sound effects and their settings) evoke for him, in thissecond database and associate these expressions with effect data withinthe first database.

Furthermore, the possibility for the user to register their ownexpressions from facial images captured by the camera enables a morereliable and precise recognition of expressions during the processingstage, for such user, as such recognition is personalized to their ownmorphology and expressions.

Correlatively, the object of the present invention is a computer programcomprising instructions for the implementation of control process stagessuch as those described hereabove, particularly when such computerprogram is executed by at least one processor.

Such computer program may use any programming language, and may be inthe form such as a source code, an object code, or an intermediary codebetween a source code and an object code, such as a partially compiledform, or in any other form desired.

Likewise, the object of the present invention includes a recordingmedium readable by a computer upon which a computer program is recordedwhich comprises instructions for carrying out all the stages of theprocess as described hereabove.

On the one hand, the recording medium may be any entity or devicecapable of storing the program. For example, the medium may comprise astorage medium, such as ROM memory, for example, a CD-ROM or ROM memorysuch as a microelectronic circuit, or a magnetic recording medium, forexample, a diskette such as a “floppy disc” or hard drive.

On the other hand, such recording medium may also be a transmittingmedium such as an electrical or optical signal which may be transferredvia an electrical or optical cable, by traditional or Hertzian radio orself-directed laser ray, or using other media. In particular, thecomputer program, according to this invention, may be downloaded via anetwork such as the internet.

Alternatively, the recording medium may be an integrated circuit intowhich the computer program is incorporated, the integrated circuit beingadapted to implement, or to be used in the implementation of, theprocess in question.

The object of the present invention also includes the control device fora generation module of sound effects, to control the sound effects of amusical instrument.

The control device according to the present invention comprises computersoftware to implement the process as described hereabove.

More specifically, the control device according to the present inventioncomprises in particular:

-   -   a capture module comprising a digital camera configured to        capture one or several digital images, each comprising at least        a portion of the user's face;    -   a computer processing module which is configured to process each        image in order to define at least one expression data containing        information relating to at least one facial expression of the        user; and    -   an analysis module which is configured to compare such at least        one expression data with a predefined first database in order to        determine at least one sound effect data which contains        information relating to at least one sound effect corresponding        to such at least one facial expression of the user, such first        database comprising a multitude of expression data, each        associated with one or several sound effect data.

The capture module comprises a camera which is sensitive tonear-infrared wavelengths.

The capture module comprises an emission medium configured to emit asource of light, preferably of infrared wavelength ranging betweenapproximately 700 to 3000 nanometers and preferably uniform, in thedirection of the portion of the user's face.

The capture module comprises a filtering medium, such as an opticalfilter, which preferably only allows the passage of a frequency band setaround to the frequency of the emitted light, before the capture of eachimage.

The control device according to the present invention comprises aninterpolation module configured to interpolate the sound effect dataand/or expression data to obtain a multitude of intermediary soundeffect data and/or expression data between two successive digitalimages.

The computer processing module is configured to enable the applicationof an image processing algorithm for each digital image to recognize atleast one facial expression of the user.

The processing module internally uses the comparison of facialdescriptors with a second database, comprising a mapping between thefacial descriptors and one or several facial expressions predeterminedor recorded by the user

Such second database comprises a mapping between facial descriptors andone or several facial expressions, which may be partially or totallylearned from facial images captured by the camera

As such, the object of the present invention, with it's variousfunctional and structural aspects, as described hereabove, provides anew approach enabling musicians to control one or several sound effects;the approach proposed according to the present invention resolves thevarious disadvantages identified in the prior art, enabling inparticular:

-   -   simultaneous control of several sound effects,    -   the possibility for the musician to use both hands for playing        their instrument, and    -   the possibility for the musician to move around on stage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Further characteristics and advantages of the present invention will behighlighted in the description herein, referring to FIGS. 1 to 3 inannex, which illustrate an example of a non-restrictive embodiment andfor which:

FIG. 1 schematically represents a control device for a generation moduleof sound effects to control one or several sound effects for a musicalinstrument according to an example of an embodiment;

FIG. 2 schematically represents a non-restrictive example of thecorrespondence map between the user's facial expressions and soundeffects; and

FIG. 3 consists of a flow chart representing the various stages ofimplementation according to an example of an embodiment of the inventionprocess.

DETAILED DESCRIPTION OF THE INVENTION

A control process for a generation module GM of sound effects, alongwith the associated control device 100 will be described hereafter inthe following description which refers collectively to FIGS. 1 to 3.

Enables simultaneous control of one or several sound effects of amusical instrument MI, while enabling the musician U to have their handsand feet free, is one of the objectives of the present invention.

The present invention therefore proposes a new way to interact withgeneration modules GM of sound effects. For this, the invention proposesa control device 100, based on an analysis in real-time of a videocapture of the musician's U face; in other words, with the presentinvention, musicians U can now control sound effects EF_(A), EF_(B),and/or EF_(C) with part of their face (for example, a mouth movement) orby simulating a general facial expression (for example, by making a“sad” or “happy” expression).

To illustrate the numerous possible embodiments of the presentinvention, the various facial expressions considered here in the presentexample are as follows (see FIG. 2): a localized facial expression, withan open mouth illustrated in EX_(a), of a localized facial expressionwith a wink illustrated in EX_(b), a general “happy” facial expressionillustrated in EX_(c), or a general “sad” facial expression illustratedin EX_(d).

Evidently, it is understood that other facial expressions (localized orgeneral) may be envisaged within the present invention (turning thehead; cheek, nostril, or eyebrow movements; a “scared” or “tired”expression, etc.).

In the example described here, the musician U first records theirdesired parameter settings: for each facial expression cited hereaboveEX_(a), EX_(b), EX_(c), EX_(d), they associate at least one sound effectEF_(A), EF_(B), and/or EF_(C).

The musician must therefore, during their first use, record on a firstdatabase DB1, during a parameter setting stage S0 a correspondence mapbetween expression data D_EX₁, D_EX₂, D_EX₃ and D_EX₄ (D_EX_(i), where iis a positive integer ranging between 1 and N, N being here equal to 4)respectively related to expressions EX_(a), EX_(b), EX_(c), and EX_(d),and sound effect data D_EF₁, D_EF₂, D_EF₃ and D_EF₄ (D_EF_(j), where jis a positive integer ranging between 1 and M, M being here equal to 4)each respectively containing information relating to at least one soundeffect EF_(A), EF_(B), and/or EF_(C).

In one embodiment, the musician may create his own expressions fromdigital images I of their face captured by the camera, to record his own“happy” expression EX_(c), or charge a predefined bank of expressions.Then, he will record an association between each expression and at leastone predefined sound effect.

In the example described here, and as illustrated in FIG. 2, soundeffect data D_EF₁ comprises information relating to sound effectsEF_(A); sound effect data D_EF₂ comprises information relating to soundeffects EF_(B); sound effect data D_EF₃ comprises information relatingto sound effects EF_(B) and EF_(C); sound effect data D_EF₄ comprisesinformation relating to sound effects EF_(C).

Evidently, this example is purely illustrative and is in no wayrestrictive; other combinations with other sound effects are possibleand conceivable for someone skilled in the art.

As stated hereabove, this parameter setting S0 may also be prerecordedon the device 100 which, in such case, comprises a first database DB1,predefined by default, comprising the correspondence map as detailedhereabove and illustrated in FIG. 2.

The present invention exploits this database DB1 through automaticrecognition of facial expressions EX_(a), EX_(b), EX_(c), EX_(d) tocontrol sound effects EF_(A), EF_(B), EF_(C) and EF_(D).

As such, the control device 100, according to the present invention,comprises a capture module M1 comprising a classic digital camera 10configured to capture, during a capture stage S1, at least one digitalimage I comprising at least a portion of the musician's U face.

Optionally, this digital camera 10 can be attached, remainingdetachable, on a pivoting arm (not shown here) to easily turn the camerain all directions so that the musician U can adjust the pivoting arm sothat the camera 10 points in the direction of their face.

This pivoting arm may be attached directly on the musical instrument MI.Preferably, this camera 10 is linked to the module by a USB connectorwhich is directly integrated within the pivoting arm.

Alternatively, this camera 10 may also be positioned further away inorder to capture the whole scene in it's field of vision.

In any event, in the example described herein, the camera 10 captures atleast one image I comprising a portion of the musician's U face.

In the example described herein, the musician U performs on stage in anenvironment presenting numerous variations in lighting and luminosity.To resolve this issue and make recognition of facial expressions moreprecise and reliable, the present invention envisages, during thecapture stage S1, the emission of a source of infrared light LUX_IR inthe direction of the musician U, using an emission medium 20 such asinfrared LED (here emitting a wavelength of 850 nanometers, but otherwavelengths are possible).

The capture module M1 furthermore comprises an infrared optical filter30, to only allow, during IRF (“Infrared Filtering”), the passage of anarrow infrared frequency band set around the wavelength emitted (thefiltered image here corresponds to a wavelength ranging betweenapproximately 840 to 860 nanometers).

The emission of a source of infrared light LUX_IR on the face of themusician U and the application of an infrared filtering IRF before thecapture of the image I, make the process insensitive to variations oflight and lighting on stage, thus making the analysis of facialexpressions more reliable, whatever the surrounding lighting conditions.

As stated hereabove, control of sound effects requires: on the one hand,the capture of one or several digital images I comprising at least aportion of the musician's U face, and, on the other hand, recognition ofone or several facial expressions of the musician U.

Such recognition of facial expressions for controlling the sound effectsof a musical instrument is characteristic of the present invention.

As such, in the example described herein, and as illustrated in FIGS. 1and 3, the control device 100 comprises a computer processing module M2which is configured to apply, during a processing stage S2, amathematical image processing algorithm on each digital image I capturedin order to recognize at least one of the user's U facial expressions.

Furthermore, it is also possible to envisage that the processing stageS2 could consist of identifying facial descriptors F_D_(k) (with k beingan integer), comprising parameters of a 3D model of a face recognized inthe image I and/or distinctive point coordinates in the image I, andcompare such descriptors with a second database DB2 comprising a bank offacial expressions which are either predetermined or recorded by themusician. This comparison enables determination of the musician's facialexpression.

In the example described herein, and illustrated in FIG. 1, using thisautomatic recognition, the device 100 recognizes expressions EX_(A)(open mouth) and EX_(B) (wink) of the musician's U face in the image I.

Expression data D_EX₁ and expression data D_EX₂ are obtained in theoutput of module M2, respectively comprising information relating toexpressions EX_(A) and EX_(B).

These expression data D_EX₁ and D_EX₂ are then analyzed by a module M3during an analysis phase S3. The analysis module M3 compares eachexpression data D_EX₁ and D_EX₂ to the first database DB1 describedhereabove to determine the corresponding sound effect data, i.e. in theexample described herein, a weighted combination of sound effect dataD_EF₁ for the “open mouth” expression and sound effect data D_EF₂ forthe “wink” expression.

The combination of sound effect data D_EF₁ and D_EF₂ is then sent to thegeneration module GM which is linked to the amplification system HP, andwhich, during stage S5, enables the production and generation of thesounds of the musical instrument associated with sound effects EF_(A)and EF_(B).

As stated hereabove, the present invention also envisages apost-processing step at output of the analysis module M3 orpre-processing before the analysis module M3 to avoid staircase effectsbeing perceived by the human ear.

As such, and as explained hereabove, the device 100 may comprise aninterpolation module M4 for a temporal interpolation of the valuesbetween two images I. This interpolation may also be used directly onexpression data.

As such, the present invention proposes a new innovative approach toeffectively control the sound effects of a musical instrument. Thisapproach provides musicians with a new tool enabling them not to bedistracted from their musical performance, and enabling them tosimultaneously control several sound effects.

It should be observed that this detailed description focuses on aspecific example of an embodiment of the present invention, but that inno case is this description restrictive of the possible uses of theinvention; on the contrary: it aims rather to avoid any imprecision orfalse interpretation of the following claims.

The invention claimed is:
 1. Control process for a generation module(GM) of sound effects to control one or several sound effects (EF_(A),EF_(B), EF_(C)) of a musical instrument (MI), such process beingimplemented using computer software comprising the following stages: acapture stage (S1), consisting in capturing, using a digital camera(10), at least one digital image (I) comprising at least a portion ofthe user's (U) face, such capture module (M1) comprising emission of asource of infrared light (LUX_IR) in the direction of the user's (U)face, and such capture module (M1) comprising application of an infraredfiltering (IRF) using an optical filter (30) to only allow the passageof an infrared wavelength band; a processing stage (S2) consisting ofprocessing such at least one image (I) to define at least one expressiondata (D_EX_(i), i being a positive integer) containing informationrelating to at least one facial expression (EX_(a), EX_(b), EX_(c),EX_(d)) of the user (U); and an analysis stage (S3) consisting ofcomparing such at least one expression data (D_EX_(i)), determinedduring the processing stage (S2) to a predefined first database (DB1) todetermine at least one sound effect data (D_EF_(j), j being a positiveinteger) containing information relating to at least one sound effect(EF_(A), EF_(B), EF_(C)), corresponding to facial expression(s) (EX_(a),EX_(b), EX_(c), EX_(d)) of the user (U), such first database (DB1)comprising a multitude of expression data (D_EX_(i)) each associatedwith at least one sound effect data (D_EF_(j)).
 2. Control processaccording to claim 1, the capture stage (S1) consisting of capturing atleast two digital images (I), wherein an interpolation stage (S4)occurs, consisting of interpolating sound effect data (D_EF_(j)) and/orexpression data (D_EX_(i)) to obtain a multitude of intermediary soundeffect data or expression data between two successive digital images(I).
 3. Control process according to claim 1, wherein the processingstage (S2) comprises the comparison between facial descriptors (F_D_(k),k being a positive integer) with a second database (DB2) comprising amapping between facial descriptors and one or several facial expressionspredefined or recorded by the user.
 4. Control process according toclaim 3, wherein the second database (DB2), comprising a mapping betweenfacial descriptors (F_D_(k), k being a positive integer) and one orseveral facial expressions, is learned partially or totally from digitalimages (I) of the face captured by the digital camera (10).
 5. Computerreadable medium containing program instructions for a computer toperform Computer program comprising instructions to implement the stagesof the process according to claim 1, when such computer program isexecuted by at least one processor.
 6. Computer readable mediumcontaining program instructions for a computer to perform Computerprogram comprising instructions to implement t the stages of the processaccording to claim 2, when such computer program is executed by at leastone processor.
 7. Computer readable medium containing programinstructions for a computer to perform Computer program comprisinginstructions to implement the stages of the process according to claim3, when such computer program is executed by at least one processor. 8.Computer readable medium containing program instructions for a computerto perform Computer program comprising instructions to implement thestages of the process according to claim 4, when such computer programis executed by at least one processor.
 9. A control device (100) for ageneration module (GM) of sound effects to control one or several soundeffects (EF_(A), EF_(B), EF_(C)) of a musical instrument (MI), suchdevice (100) comprising: a capture module (M1) comprising a digitalcamera (10) configured to capture at least one digital image (I)comprising at least a portion of the user's (U) face, such capturemodule (M1) comprising emission of a source of infrared light (LUX_IR)in the direction of the user's (U) face, and such capture module (M1)comprising application of an infrared filtering (IRF) using an opticalfilter (30) to only allow the passage of an infrared wavelength band; acomputer processing module (M2) configured to process such at least oneimage (I) in order to define at least one expression data (D_EX_(i), ibeing a positive integer) containing information relating to at least onfacial expression (EX_(a), EX_(b), EX_(c), EX_(d)) of the user (U); andan analysis module (M3) configured to compare such at least oneexpression data (D_EX_(i)) with a predefined first database (DB1) todetermine at least one sound effect data (D_EF_(j), j being a positiveinteger) containing information relating to at least one sound effect(EF_(A), EF_(B), EF_(C)), corresponding to facial expressions(s)(EX_(a), EX_(b), EX_(c), EX_(d)) of the user (U), such first database(DB1) comprising a multitude of expression data (D_EX_(i)) eachassociated with at least one sound effect data (D_Ef_(j)).
 10. Device(100) according to claim 9, capture module (M1) configured to capture atleast two digital images (I), characterized in that it comprises aninterpolation module (M4) temporally interpolating the effect data(D_EF_(j)) and/or the expression data (D_EX_(i)) to obtain a multitudeof intermediary effect data or expression data between two successivedigital images (I).
 11. Device (100) according to claim 9, wherein theprocessing module (M2) comprises the comparison between facialdescriptors (F_D_(k), k being a positive integer) with a second database(DB2) comprising a mapping between facial descriptors and one or severalfacial expressions predetermined or recorded by the user.
 12. Device(100) according to claim 11, wherein the second database (DB2),comprising a mapping between facial descriptors (F_D_(k), k being apositive integer) and one or several facial expressions, is learnedpartially or totally from digital images (I) of the face captured by thecamera.